appendix a laguna division conservation area: …...appendix a laguna division conservation area:...
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Appendix A Laguna Division Conservation Area: Project Update for the MSCP Steering
Committee. October 2010
Laguna Division
Conservation AreaConservation Area
Project Update
Project Site MapProject Site Map • Project Area – 1154 acres
• Reach Length – 4.3 miles
• Existing Conditions - Extensive/dense tamarisk
monoculture
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Project Design ConsiderationsProject Design Considerations • Up to 100 cfs available for project use • Habitat Targets
• Open Water/Marsh: 50 – 100 ac • Cottonwood/Willow: >200 acCottonwood/Willow: >200 ac • Upland(mesquite): <500 ac • Include specific habitat for T&E species
• P id h d l h bi f 50 Provide hydrology to support habitats for 50 years or more • No detrimental effect on existing Mittry Lake or Old River Channel
Habitats • Minimize impacts to existing operations (sluicing, dredge disposal,
water delivery, etc.) • Minimize both initial construction and long-term operating costs
Target HabitatsTarget Habitats Open Water/Marsh: 50 – 100 ac
Upland (Mesquite): <500 ac Cottonwood/Willow: >200 ac
Target Species California Black Rail
Yuma Clapper Rail
Southwestern Willow Flycatcher
Yellow Billed Cuckoo
Yuma Hispid Cotton Rat
Colorado River Cotton Rat
Western Least Bittern
Permitting UpdatePermitting Update • NEPANEPA
– Public Outreach held in March 2010 – Draft NEPA September 2010Draft NEPA September 2010 – Final NEPA October 2010
•• 404 Permit 404 Permit – Scheduled submittal November 2010
Addi i l P i• Additional Permiitting – Yuma County encroachment permit for road
crossing
Public Concerns with BurnPublic Concerns with Burn
• N b A i lt Fi ldNearby Agriculture Fields – Wind direction for ash fallout Bureau of Land Management – Displaced Animals will address these in final burn plan
• Wildlife and Wildlife Areas Wildlife and Wildlife Areas – Breeding Season – Displaced Animals – Recreation at Mittry Lake Wildlife Area
• Nearby Homes and Parks – Road Closures – Smoke / Ash fallout – Fire Containment Fire Containment
• Invasive Weeds – Spread of Invasive Weeds by Fire Management Operations
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General Project Update
• Boundary change – Additional acres from
dredge disposal sitedredge disposal site
– Tribal boundary revised • Designing preferredDesigning preferred
alternative • Moving towards
constructiion
=
REACH 1
REACH 2 “Pulse” WSE = 159.0
“Pulse” WSE = 157.0 REACH 3
Normal WSE = 157.0 WCS#1 Normal WSE = 150.0 Normal WSE 150.0
GILA Channel Invert = 151.0 Channel Invert = 148.0 WASTEWAY Channel Invert = 149.0‐150.0
Normal WSE = 155 0 WCS#2
Normal WSE 155.0
CANAL CONNECT TO THE
OLD RIVER CHANNEL
Current Design Concept: OverviewOverview
• Operate as a managed Operate as a managed, leveed wetland rather than a river• leveed wetland rather than a river system to maximize limited water resource
• Use existingg overflow channels througgh pprojject area to minimize excavation
• Use “pulse flows” to provide irrigation to woody species • Requires water control structures to manage water levels
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Construction ComponentsComponents
• Water Delivery System from Gila Forebay •• HeadworksHeadworks • Pipeline
• Site Preparation for Earthwork • Burning and Grubbing of Salt Cedar
• Earthwork • Channels provide the topography to support
water conveyance and vegetation/ habitat • Utilize existing topography to minimizeUtilize existing topography to minimize
cut/fill and maximize pulse flow irrigated area
• Reach 1 & 2 primary and secondary channels; Reach 3 outlet channels; E hEnhancement of hi f historiic chhannell
• Levees and roads for access and firebreaks
• Water Control Structures • Managge water levels in Reaches 1 & 2,, and
historic river channel • Additional Mittry Lake turnout structure
Water Deliveryy System Overview • GGravit ity systtem ddeli liveriing hihi ghh
quality water from the Gila Forebay to the wetland restoration area
• Pipeline headworks at the Gila Forebay
• 2,300-FT, 48-IN. diameter pipeline
• Cross underneath the Gila Wasteway Canal with an inverted siphoninverted siphon
Gila Forebay
near proposed headworks
Water Delivery System: Headworks
• 5-day construction window during maintenance draw-down for the Gila Forebay
• Construct cast-in-place concrete stop-log bay during the maintenance draw-down (Tentative start date: January 2011)
• Construct pipe penetration/closure of the Gila Forebay liner and install secondary slide gate (Tentative start date: Spring 2011)
• Install primary valve and meter (Tentative start date: Spring 2011)
Water Delivery System: PipelineWater Delivery System: Pipeline
• 4848-inch diameter 2 300 Foot pipelineinch diameter, 2,300 Foot pipeline – Inverted siphon to cross underneath the Gila Wasteway
Canal – Scheduled to be constructed Spring 2011 Scheduled to be constructed Spring 2011
• Constructed through portions of the original Yuma Proving Grounds historic area SHPO consultation Proving Grounds historic area – SHPO consultation underway
Site Prepparation for Earthwork • Prescribed Burn
– Single burn of entire project area – BLM developing burn plan – Scheduled for fall/winter 2011
• Post Burn Operations Post-Burn Operations – Clearing, Grubbing & Piling – Soil & Water Monitoring – O i h bi id t t t f i iOn-going herbicide treatment of invasive speciies
Earthwork Operations: T i l C S ti Typical Cross Sections
Earthwork Opperations • Earthwork
– Approximatelyy 1.3 Million Cubic Yards of excavation pp – Utilize excavated spoils to form levees and
maintenance roads
– Excavate from south to north to allow management ofExcavate from south to north to allow management of groundwater
– Commence Fall 2012
• Invasive weed management on goingInvasive weed management on-going
Water Control StructuresWater Control Structures • Overshot Gates set in cast-in-place concrete bays
• Constructed in concert with earthwork operations
• Potential to automate
•• Additional Mittry Lake turn out structure Additional Mittry Lake turn-out structure
Habitat Acreages
Channel Revegetation (Tidal irrigation with water control structures)
April 2006
June 2010
Marsh and Transitional Zone (Tidal irrigation with water control structures)
October 2005
June 2010
Transitional Zone (Tidal irrigation with water control structures)
October 2006
June 2010
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Plant Establishment 1. Establishment of marsh plantings and upper terrace
mesquite plantings - Hand planting of marsh plugs and deep pot mesquitesHand planting of marsh plugs and deep pot mesquites - Marsh plants must establish before the transitional/cottonwood
areas can be flooded M i l i i i d i h h i i i i l l d-Mesquite plantings irrigated with sheet irrigation in leveled areas
2. Establishment of transitional zones and cottonwood/ willow once marsh plants are tall enough to flood for longer periods (4-6 months after marsh plantings)
M hi l d i h l d/ h d l i i h l 1- Machine planted with plugs and/or hand planting with larger 1 gallon trees
Plant Establishment 3. Water level management
- Freqquent fluctuations the first two yyears duringg establishment - Once vegetation is established maintain stable water levels
especially during migration and nesting seasons
Project Maintenance and MonitoringProject Maintenance and Monitoring
• Follow up aerial/land-based herbicide treatments after Follow up aerial/land based herbicide treatments after burn and up to planting areas
• Continued weed maintenance of planted/unplanted areas during plant establishment period (intense maintenance the first 2-3 years)
•• Maintenance and operation of water control structures Maintenance and operation of water control structures, roads and project infrastructure (50 years)
• Irrigation of upper terrace mesquite revegetation • Plant and wildlife monitoring of restored area • Long-term weed, replanting and irrigation maintenance
Additional Information NeedsAdditional Information Needs
• Additional Monitoringg Wells alongg Pro pposed Channels – Groundwater information (water quality and salinity)
• Additi l il t d t i th d th t Additional soil surveys to determine the depth to watter table, soil texture and soil salinity across the site
• Vegetation design will need refinement to incorporate the additional water and soil analyses
Current Schedule
Questions?